# Comparative Analysis of Microbial Detection in Traditional Culture Versus Metagenomic Next-Generation Sequencing in Patients with Periprosthetic Joint Infection: A Prospective Observational Study

## TL;DR

This study compares traditional culture and metagenomic sequencing for diagnosing joint infections, finding that sequencing detects more pathogens.

## Contribution

The study demonstrates that mNGS outperforms traditional culture in detecting pathogens in periprosthetic joint infections.

## Key findings

- mNGS identified pathogens in 66.7% of patients, while traditional culture found them in 28.6%.
- Staphylococcus species was the most commonly detected genus using mNGS.
- mNGS detected a wider range of bacterial genera compared to traditional culture methods.

## Abstract

Identifying pathogens causing periprosthetic joint infection (PJI) is a challenge for clinicians. We aimed to evaluate the application of metagenomic next-generation sequencing (mNGS) to identify pathogens in PJI. A prospective analysis was conducted of patients diagnosed PJI between 2022 and 2024 at twelve hospitals in Taiwan. Both conventional bacterial culture (CMT) and mNGS of joint fluid and debrided tissue were performed. Demographic characteristics, laboratory results and clinical outcomes were collected. The diagnostic performance of these two methods was analyzed. A total of 42 patients with a mean age of 67.9 years were enrolled in analysis. The knee was the most common joint involved (69.1%). A high proportion of patients (78.6%) received prior antibiotics within the two weeks at sample collection. mNGS identified pathogens in 28 out of 42 patients (66.7%), whereas CMT yielded positive results in 12 out of 42 patients (28.6%) (McNemar’s test, p = 0.01). Staphylococcus species was the most common genus detected (n = 11), followed by Cutibacterium (n = 4). Other detected genera included Escherichia, Mycobacterium, Enterobacter, Klebsiella (n = 2 each), Acinetobacter, and Corynebacterium (n = 1 each). Our results support the idea that mNGS could serve as a valuable diagnostic tool for PJI in addition to traditional culture methods.